Ultra-High Performance Concrete (UHPC) is a type of concrete that was developed by agencies concerned with infrastructure protection. UHPC is characterized by being a steel fibre-reinforced cement composite material with compressive strengths in excess of 150 MPa. UHPC is also characterized by its constituent material make-up: typically fine-grained sand, quartz powder, silica fume, small steel fibers, and Portland cement. It is substantially free of large aggregate.
Reactive powder concrete (RPC) is one of the most widely used type of UHPC, which provides combinations of ultra-high strength, high ductility, and excellent durability characteristics.
Conventional reactive powder concrete (RPC) includes between 800 kg/m3 and 1000 kg/m3 of cement particles smaller than 100 μm, between 25 and 35 wt % of silica fume with particles between 0.10 and 0.20 μm, between 0 and 40 wt % of crushed quartz (or quartz powder) with particles smaller than 100 μm, between 110 wt % and 140 wt % quartz sand with particles between 150 and 630 μm, and 2.5 wt % of steel fibers. The percentages are based on the total cement content of the mix by weight. It is also characterized by a low water to binder ratio, typically between 0.11 and 0.25 as well as high amount of superplasticizer.
The RPC is designed with a high cement content ranging between 800 and 1000 kg/m3. Furthermore, estimate of the final hydration percentage of the cement in the UHPC ranges from 31 to 60% due to the very low water-to-cement ratio (w/cm). This huge amount of cement not only affects the production cost and consumes the natural sources of limestone, clay, coal, and electric power, but also has a negative effect on the environmental conditions through the carbon dioxides (CO2) emission, which can contribute to the greenhouse effect. This can be illustrated by knowing that the production of 1.0 ton of cement (clinker) can emit approximately 1.0 ton of CO2. The RPC fabrication requires a relatively high content of silica fume due to its extreme fineness, high amorphous silica content, as well as the physical (filler, lubrication) and pozzolanic effects. This high content of silica fume with limited resources and high cost is considered as one of the impedances of the RPC use in the concrete market. There is thus a need for other materials with similar functions to partially or fully substitute the silica fume in RPC. On the other hand, the use of quartz sand (QS) and quartz powder (QP) in the RPC do not satisfy the sustainability requirements. Also, silica fume, quartz sand and quartz powder are very expensive.
Glass is a material produced by melting a number of materials including silica, soda ash, and calcium carbonates (CaCO3) at a high temperature followed by cooling during which solidification occurs without crystallization. The glass can be recycled so many times without significant alternation of its physical and chemical properties. Large quantities of glass cannot be recycled because of breaking, color mixing, or expensive recycling cost. The amount of waste glass is gradually increased over the recent years due to an ever-growing use of glass products. Most of the waste glasses have been dumped into landfill sites, which is undesirable as it is not biodegradable and less environmentally friendly. Therefore, there is a need to find products in which waste glass can be incorporated.